Concrete block



FIG. 1 is a top plan view of a concrete block showing my new design;

FIG. 2 is an end view of the narrow end of my block;

FIG. 3 is a left side view of my block;

FIG. 4 is a right side view of my block; and

FIG. 5 is an end view of the wide end of my block; 

The ornamental design for a concrete block, as shown. 